Signaling system



2 Sheets-Sheet 1 J. H. woor'roN SIGNALING SYSTEM mea sept. v. 1922 May l2, 1925.

ATTORNEY May 12, 192s. 1,537,211

.1. H. wooTToN S-IGNALING SYSTEM.

Fil-ed Sept. '7, 1922 2 Sheets-Sheet 2 Jo/Uz H. Woozion.

ATTORNEY ,Patented May 12, 192s'. T f-UNITED STATES PArENroEFicE.

JoHN n. Woocr'roN, or NEW Yoann. Y.

SIGNALING SYSTEM.

appuc'ation med september 7, 1922. serial no. 586,736.

To all whom it may conce/m:

Be it known that; I, JOHN H, Woor'roN, a citizen of 4the United States, residing in lthe borough of -Manhattam in the city,

' automatic fire alarm systems which are 1ntended for response to the closure ofthe normally open contacts of thermostatic devi-ces, or the like) in which all current carrying parts should be' under constant test, in which it is desirable to minimize the normal test current, and in which a current greatly in excess of the normal test current should be available for active signaling.

respectively vresponsive to t adjusters, which manifesting stationsmayy d of circuit lcontrollers, the switchfor such An object of this invention is to provide a system of the character described in which all current carrying under constant test.

Another object is to provide construction and arrangement of partswhereby a single current source may be utilized for ma1ntaining a normal test current; for energizing` the tripping magnets of 'annunciator units in response to the operation of circuit ad- 'I justers, groups of which may be associated therewith; and for manifest4 ing warning signals at manifest-ing stations e operation of such circuit be located in close proximity to or scattere at considerable distances from such annunciator units.

' l Other objects and aims of this invention,

more or less specific than those just referred to, will be in part obvious and in' part pointed out in the course of the following description.

For the purpose of enabling this invention to be more readily understood, a typical illustrative embodiment thereof is shown in the annexed drawing and hereinafter described in detail, but this invention is not limited to 1such embodiment, as many changes may be made in construction and arrangement, and parts mayA be added or omitted Without departing from the spirit of this invention.

Like reference characters denote similar parts will, be A parts .throughoutthe accompanying draw- I ings, in Which- Figure 1 diagrammaticallyillustrates a typical signaling system embodying this invention, and i Fig. 2 is a simplified schematic representation of the circuit arrangement of Fig. 1. i The signalin system illustrated by Fig.

1 comprises a p -urality of circuit controllers .arranged in five groups generally designated as AfB, C, D and E, which are respectively associated with the annunciator units a, 5,.

c, d' and c; which annunciatorA units, together with the alarm devices R connected in the'alarm groups F and G, and the alarm loop controlling contacter H, constitute alarm manifesting mechanisms, while the Y trouble bell J, its controlling relay K,and the associated ammeter L comprise supervisory manifesting mechanism. y

The current supply for the entire system (with the exception of the local circuit ori the trouble .bell J is 'provided by the cur-l rent source P; and a .system of conductors is provided, which system is so arrangedthat a normal current path is provided from said source P, which path includes the Windl -ings and contacts of all ofsaid devices, ex-

cepting only, as already stated, the local current path lof the trouble bell J. The

four-pole double-throw switches, generally indicated-by .the 'reference letter Q, are iny dividually associated with respective ones of the ,circuit controller groups A, B, C, D and E; so that in the event of the develop# ment of a break or other fault in the conductors connecting any one of said groups tem may function in the intended manner.

while such grbup of circuit controllers are so disconnected therefrom.

'Eachr'of' the circuit controllers of the groups A, B, C, D. and E comprises the normally open closable contacts 21 and 22;

and said controllers may consist of any wclllrnown form of thermostatic or other device having contacts which are normally disconnectedbut which can be brought into engagement, in any desiied signal manifestations. Q y r[he annunciator units a, b, c, d and e desired manner, one with the other, for the purpose of causing 11o retracted, to hol in the path of the conductor 45,

ture 25 one end of which is pivoted to the pole piece 264 and the', other end of which is disposed -adjacent the pole piece 27, andl a retractile spring 28 so applied to. the armature 25 as to of said amature away from the pole piece 27 and to bring said armature .into engage--.

ment with the stop 29. A gravity shutter 30 is hinged at l31 and is arranged so that, when said shutteris in its normal position, it may be engaged by the armature 25, if

said shutter against movement to its abnormal position; and so that, when said armature is 'in its attracted position,V said shutter will be. free to move from its normal to its abnormal position.

The contactor H comprises an electromagnet 32, its armature 33, and a contact member 34 carried by andinsulated from said armature. The

member 34, so as to furnish a backstop for limiting the retractive movement of the armature 33; and the contact 36 is mounted in the path of the attractive movement of said armature, and the contact 37 in that of the member 34, to the end that, when said armature 33 is in its attracted position, said armature and member will be in contact with said contacts -36 and 37, respectively. i

The'relay K comprises a highfresistance electromagn'et 40, its armature 41, and the backstop contact 42; said armature 41 being connected by the conductor 43 with one terminal of the battery 44; the other terminal of said battery being connected throu h the the bellJ and the conductor 46 to the back stop 42. It will thereforebe evident that so long as the electromagnet 40 is eli'ectivelyenergized, the armature 41 will remain in attracted position and the current path through the bell J will be interrupted; and that, when said electromagnet is not effectively energized, said armature 4l `w1l1 move to its retracted position, thereby establishing a connection with the back stop 42 and closing a currentpath from the battery 44 through the bell J, so as to cause said bell to sound, for a purpose which will be hereinafter more fully explained.

The alarm devices represented as typical any desired form of signal manifesters; such R, diagrammatically devices being so constructed and arranged. vthat they will not act in current flow'in the` response to either making or breaking of u circuit in which they are included, unless such current iiow equals a certain predeter-v mlned intensity; and

so that. such devices will cause a desired signal manifestation in response to current flow in the circuit in which they are connected, equaling or exceeding such predetermined intensity.

A54 normally engage tend to move the free end abutment 35 is situated `,te-rect the effect bells, may consist of'- said winding,

annunciator unit e,

'ductor 116 to one endof th Each of the switches Q comprises the hinged blades 51, 52, 53 and 54, the free ends of which blades are secured to the tinsulating yoke 55; to which yoke the operating handle 56 is attached. The blades 51, 52, 53 and the jaws 57, 58, 59 and 60, respectively; but upon reversal of such blades they may' bebrought into engagement with the jaws 61, 62, 63 and 64, respectively; the jaw 61 being permanently connected to the jaw 64 by means of the conductor 65 and the jaws 62 and. 63 connected by the conductor 66.

The normal current path from the source P is as'follows: from one terminal of said source, through conductor 101, and. armature 33 of contactor H, to onej end of the winding of the electro tor; thence throu through conductor 103 to one end ofthe winding 23 of the'annunciator unit a; thence h conductor 105, Athrough either the contact 21 or the contact 22 of each of the circuit controllers of group A, through jaw 60 and blade 54 of said switch Q, and through conductor 106 to one terminal of the dili'erential winding 24 of the annunciator unit a; thence through such winding of said unit in such direction as to counof winding 23, through conductor1072 through the blade 52 and jaw 58 of the swltch Q associated with grou B of said circuit controllers, through conductor 108 andthrough either the contact 21 or the contact 22 ofeach of the circuit controllers of said group B, through .jaw 59 and blade 53 of said switch Q, and through conductor 109 to one terminal of the winding 23 of the annunciator unit c; thence through s'aid winding and through conductor 110, through the switch Q associated with group C of circuit controllers,and through the conductor 105 and the contacts of said controllers as in the case of group A, through conductor 111 and winding 24 of said annunciator unit c as in annunciator unit a, already described; thence through conductor 112,v the switch Q, conductor v108 and contacts of circuit controllers of group being permanently b l agxnet 32 of said contacg said winding and 1) 1n a manner corresponding to that of group .as hereinbefore described, and through conductor 113 to one terminal of the winding 23 of annunciator unit e; thence `through through conductorI l114, through switch Q, conductor 105 and contacts of circuit controllers of group E, as in group A hereinbefore described, through conductor 115 to and through winding 24 of as in annunciator unit a hereinbefore described; thence through cone winding of the'. electromagnet--40 of the relay K, through i of group E in a manner corres tactor H, through lished therethrough,

said Winding, through the conductor- 117, through the ammeter L and through condnctor 118 `to and through the switch Q, conductor 108 and contacts of circuit control- 1ers of group A, as through grou B here@ inbefore described; thence throng conductor 11,9, through the differential, windings of the annunciator unit b, through conductor '120, the switch tacts of circuit controllers of group B and conductor 121, in afl'anner corresponding to that hereinbefore described in` detail or the first current path through annunciator unit L and group A' thence through conductor 122, switch conductor v108 and contacts of circuit controllers of group C in a manner corresponding to that hereinbefore described in Vdetail for the first currents path through group B; thence through conductor 123, the windings of annunciator unit d, through conductor 124, the switch Q, conductor 105, contacts of circuit controllers D and conductor 125, in a manner corresponding to that hereinbefore described in detail for the irst current path through annunciator unit a and gro-up A; thence through conductor 126, switch Q, conductor 108, contacts of circuit controllers of group ending to that here` inbefore described in etail for the first current path through group B; thence through conductor 127 to Contact member 34 of con-' said member and through conductor 128, through the devices R serially included therein, to contact 36 of said contactor; thence through said contact and cor-V respondingly through conductor 129 and the devices R of group G to contact 37 otsaid contactor;'thence through said contact and through conductor 130. to the other terminal of the current source P.

From the foregoing it will be seen that, under normal conditions, a test current path is maintained through each of the contacts of each of the circuit controllers of the groups A, B, G, D and E; through each of the windings of the annunciator units a, b, c, d and c; through thel electromagnet windings of the relay K; through the ammeter L; through all ot' the alarm devices R and through all of the current carrying parts of the contactor H. c

rI;`he resistance of the winding of the electromagnet 40 of the relay K is so high thatwhen the normal current path is estbas just described, the intensity of the currenttlow from the source P therethrough-'will be insuiticient to cause responsive action of the devices R, and will constitute an extremely small drain upon the capacity of the source P; the said'relay K being so adjusted that in the event of the interruption of thenormal current path just described, or of such diminution of current flow. therethrough as would occur in the` Q, conductor 105, con-l' '"al, conductor event that the electromotive :torce of said current source was diminished to a point insuiicient `to cause intended operation of thev apnunciator units, contacter and alarm de- .vi'cesf (asf hereln after l more fully explained), the armature 41 'o said relay will move to retracted position, and thereby cause a.

warning signal to 'be sounded by the vbell J.

As hereinbefore statedgthe normal current path through the differential windings of the annunciator units a, b, c, d ande is so arranged that one of said windings neutralizes the other in' each of said units and said units may be so arranged as responsive to normal test current flow through one of the windings thereof, even in the absence of'opposing energization of the other winding ciator. units should be so arranged that in the event of current flow through one of the to be unthereof; but such annun-fwindings thereof in predetermined excessof s that through the other winding, the armature 25 of such unit will be moved to attracted position and the shutter 30 will thereupon drop to indicating position.

The contactor H is so arranged that current flow therethrough of such intensity as occurs from the source mal current path hereiuhefore described in detail will not cause effective energization oit the electromagnet 32 of such contractor, and so that current ow'through said magnet of predeterminedexcess above such normal flow will cause sufficient energization of the magnet 32 to cause the armature 33 to P through the normove into engagement vwith the Contact 36,

and thereby carry the member 34 into en gagement with the contact 37.

As most clearly shown by Fig. 2, this sys- *tem comprises a signal circuit having two parallel loops, one end of one of which loops is connected with the opposite end of the other of said loops through the supervisory signal manifesting the high resistance relay K and the meter L; the current source P and alarm mechanism comprising the contactor Hl and the devices R being connected between the remaining ends of said loops. y

In detail, one of said parallel loops comprises, 103, the winding23 of the annunciator unit the switch Q. associated with group A, conductor and either theievontact 21 or the Contact 22 of each of the circuit controllers of said group, the jaw winding 24 means comprising in the order stated, the conductor 104, the blade'51 and jaw 57 of Y n 60 and blade 54 Vof v`said switch, the conductor 106,

ofthe annunciator unit Y1., conductor 107,

switch Q, conductor 109, winding 23 of an- B, conductor 108 and I nunciator unit c, conductor 110', the blade 51 and jaw 57 of the switch Q associated with group C, conductor 105 and either the Contact 21 or the contact-,2 2Iof each of the circuit controllers of said group,.the jaw and blade 54 of said last named switch Q, conductor 111, winding 24 ofannunciator unit o, conductor 112, blade 52 and jaw 58 of switch Q associated with group D, conductor 108 and leither the contact 21 or the contact. 22 of each of the circuit controllers of said group, jaw 59 and blade 53 .of said last named switch Q, conductor 113, winding 23 of annunciator unite, conductor 114, blade 51 and jaw 57 of the switch Q associated with group E, either the contact 21 or the contact 22 of each of the circuit'controllers of said group, jaw, 60 and blade 54of said .last named switch Q, conductor 115, winding 24 of annunciator unit e, and conductor 116.

The other of said parallel loops leads to said groups of circuit controllers in reverse order and includes the windings of the annunciator units which are not included in said first named group; and said other loop comprises, in the order stated, conductor 127, the blade 53 and jaw 59 of the switch QV associated with group E, conductor 108 and the contacts of the circuit controllers of such group which were not serially included in the first described loop, the jaw 58 and blade 52 ot' said switch, conductor 126, winding 24 of annunciator unit d, conductor 125, blade 54 and jaw 60 of the switch Q associated with` group D, conductor 105 and the contacts of the circuit controllers of such group which were not serially included in the first described loop, jaw 57 and blade 51 of said last named switch Q, conductor 124, winding 23 of annunciator unit d, conductor 123, blade 53 and jaw 59 of the switch Q associatedwith group C, conductor 108 and the'oontacts of the circuit controllers of such group which were not seriallyineluded in the first described loop, jaw 58 and blade 520i.: said last named switch Q,

. scribed loop,

conductor 122, winding`24 of annunciator unit b, conductor 121, blade 54 and jaw 60 of the switch Q associated with group B, conductor 105 and the contacts of the circuit controllcrs of such group which were not serially included in the first described loop, jaw 57 and blade 51 of said last named.'

switch Q, conductor 120, winding 23 of annunciator unit. conductor 119, blade 53 and jaw 59 of the switch Q associated with group A, conductor 108`and the contacts of the circuit controllers of such group which were not serially included in the first dejaw 58 and blade 52 of said last named switch Q, and conductor 118.

By virtue of the novel signal circuit arrangement hereinbefore described in detail, it will be seen that closure ofthe contacts conductor 105 and `of any controller will establish a current path from the source P including one of the differential magnet windings of the associated annunciator unit, the windings of `the alarm mechanisms'H and R and the:

ance relay K, the current flow therethrough' will be still further augmented.v

In the use by the drawings, all arts are normally positioned as shown, and) the normal test or su.- pervisory current path is as hereinbefore described in detail; the vbell J and devices R being inactive because the energization of magnet 40 of relay K causes interruption ofthe current path through said'bell J, and because the test current path effective through said devices R includes the two parallel loops hereinbefore described in detail and the high resistance relay K and meter L. The high resistance of the current path thus normally effective minimizes the drain upon the current source P so that battery cells may be employed for such source and along service life secured therefrom.

In 'the event that a connection is established between the contacts of any one of the circuit controllers, the shutter of the annunciator unit associated with the group of which such controller forms part will move to indicating osition, the electromagnet of the contactor 1 will be effectively energized and the armature of said contactor will thereupon move to attracted position, and the devices R of groups F and G will thereupon be connected in parallel across the terminals of the current source P, so that said devices will give intended warning of the closure of such contacts. The closure of the contacts of' any circuit controller, as just described, will terminate the effective energization of the magnet 40 of relay K, and the armature 41 of sai-d relay will thereupon move to retracted position, thereby causing the bell J to sound. Thereafter, upon separation of the contacts of such active circuit controller, or, in the absence of such separation, upon reversal of the switch Q associated with the group of which such circuit controller forms part, the relay K and contactor H will be restored to their respective normal conditions, and thereupon the activity of the bell J and the devices 2R will cease.

`Assuming, is established of one of the for example, that a connection between the contacts 21 and 22 circuit controllers of group A,

the current flow will be at least double that l ,so of the signa-ling system shown l a current path will be established from one terminal of the source P, through conductor 10.1, armature 33 and winding 32 of contacter ll, conductor 103, winding 23 ot annunciator unit a, Conductor 104, blade 51 and jaw 57 of switch Q associated with group A, conductor -105 and the closed contacts of the active controller, conductor 108, jaw 59 and blade 53 of said switch Q, conductor 119, winding 23 of annunciator unit b, conductor 120, blade 51 and jaw 57 of thc switch Q associated with group B, conductor 105 and either the contact 21 or the contact 22 of each of the circuit controllers ot said group, jaw 60 and blade 54 ot said last named switch Q, conductor 121, winding 24 of annunciator unit b, conductor 122, blade 52 and jaw 58 of switch Q associated with group C, conductor 108 and either the contact 21 or contact 22 of each ot the circuit controllers of said group, jaw 59 and blade 53 of said last named switch Q, conductor 123, winding 23 of annunciator unit d, conductor 124, blade 51 and jaw 57 of the switch Q associated with group D, conductor 105 and either the contact 21 or the contact 22 of each of the circuit controllers of said group, jaw 60 and blade 54 of said last named switch Q, conductor 125, windin 24 of annunciator unit d, conductor 126, blade 52 and jaw 58 of the switch Q associated with group E, conductor 108, and either the contact 21 or contact 22 offeach of the circuit controllers associated with said group, jaw 59 and blade 53 of said last named switch Q, conductor 127, member 34 of contacter H, conductor 128 and devices'.

R of group F, *contact 36 of contacter H, conductor 129 and devices R of group G, contact 37 of contactor H, and conductor 130, to the other term-inal of source P.

Upon the establishment of the current path just described, the electromagnet 32 of the contacter H will be effectively energized, the armature 33 will thereupon move to attracted position; thus establishing three par-- allel current paths across the Aterminals of the current source P. One of said three current paths will constitute the signaling circuit current path comprising the condilctor 101, armature 33 and Windin of the electromagnet 32 of the contacter gl and the conduc'toi1 103, thence through the signaling circuit current path hereinbefore just described in detail to and through conductor 127, thence through member 34 and contact 37 oi" contacter H, and conductor 130. Another'of said three current paths will constitute the current path through the devices R of group F, comprising the conductor 101, armature 33 and contact 36 of the contactor Il, the conductor 128, and devices R serially included therein, the member 34 and contact 37 of said contactor, andthe conductor 130. The other of said current paths will constitute the current path through the devices R ol' group (l, comprising the conductor 101, armature 33 and contact 36 oi. the contacter ll, the conductor 129 and devices R serially connected therein, the contact 37 of said contacter, and the conductor 130. When the three current paths have been established, as just described, the electromagnet of the annnnciator unit a will be effectively energized, its armature 25 will be in attracted position, and its shutter 30 will be in indicating position; and the devices R of groups F and C' will give the intended alarm manifestation.

Should circuit controllers of two or more groups close simultaneously or concurrently, annunciator units associated with such groups will actin a predetermined manner,

which will be best understood by a perusal of the following examples: If connections are established between the contacts of circuit controllers of groups A and B, winding` 23 of annunciator unit a. will have full alarm current energization and winding 24 of said unit will have one-half such energization, the winding 24 of unit b will have full alarm current energization and the winding 23 of said unit will have one-halt said energization; the windings of units c'and e will have a mere nominal energization, while the windings of unitd will have full alarm cur rentenergization. Inasmuch as the current so tranverses the differential windings of units @,CZ and e as to cause such windings to act in opposition one to the other, the mag'- nets of said units will not be e'ectively energized, but the magnets of units a and 5 will be effectively energized, and their shutters 30 will therefore move to indicating position. If connections are established between contacts of circuit controllers in groups A and C, the annunciator units a and c will correspondingly act in response thereto.

It contacts of circuit controllers in three or more groups close simultaneously, the annunciators of the first and last of such groups (in the order in which they are connected in the alarm circuit loops) will respend to such closures.l For example, if connections are simultaneously established between contacts o circuit controllers in groups A, B and C, annunciator units a and o will respond.

In this connection it' is pointed out that, as iswell understood by those skilled in this art, it would be very unusual for contacts of circuit controllers in two groups to close one after another so that the first to be estabclosure between lished will cause responsive actionv of its' associated annunciator unit.

It is ordinarily deemed preferable that all annunciator units shall not act in response to the closure of contacts of circuit controllers in all or a considerable number of groups; but, rather, that such annunciator units shall indicate the start and end of the series of groups having active circuit controllers. For example, assuming that the circuit controllers of groups A, B, C, D and E are distributed upon the fifth, fourth, third, second and first stories of a building, respectively, and that such controllers are operable as fire detecting thermostats,- should a fire occur in the first story, contacts of one or more circuit controllers in group E would close, thereby sounding an alarm and causing the anniinciator unit e to act to show that the tire was on the first iioor; while, should there be a flash fire involving the Erst, second and third floors,`the alarm would sound and (assuming that contacts of the circuit controllers of all three floors closed simultaneously) annunciator units c and c would act, thus indicating` that the areaA of the building from the first to the third floors, inclusive, y'as involved.

In the event of failure or operative iinpairment of the connection between either the contact 2l or the contact 22 of any circuit controller and its associated conductor 105 or 108 (as the case may be), or of the electrical connection between any one of the alarm devices R and its associated conductor, current How through the test current path hereinbefore described in detail would be thereby interrupted or substantially decreased, whereupon the electromagnet tflteof the relay K would no longer sustain tie armature L11, and said armature would move into engagement with the backstopfQ, and thereby complete the circuit` through the trouble bell J.

It will be evident to those skilled in `this art that the use of the meter L is optional, and that the relay K may be o1nitted, if it is not desired to provide ay supervisory trouble signal such as that shown. In the event of the omission of both the relay K and the meter L, the conductors 116 and 118 may be directly joined: although it will usually be found desirable to provide a hi; h resistance connection between such conductors, in order to suitably minimize the drain upon the current source P. Ilven if the conductors 11G and 11S are joined without the use of a resistance therel'ietween, the annunciators and alarm devices will operatein the desired manner, responsive to the contacts of any of the circuit controllers, so long as the magnet windings of succeeding annunciator units are connected, as described, in alternate ones of the two parallel signal circuit loops.

It will also be evident that other changes may be made in the construction and arrangement of the system shown by the accompanying drawings and hereinbefore described, without departing from the spirit of this invention.

That I therefore claim and desire to secure by Letters Patent of the United States of America is:

1. In a signaling system, a signal circuit.

two parallel loops, a. high i'esistance connection between one end of one of said loops and the opposite end of the other thereof, signal manifesting means arranged for response to variations of current flow through said connection, a current source and signal manifesting means connected between the remaining ends of said loops, signal devices each having a differentially wound eleetromagnet, magnet windings of succeeding devices connected in alternate ones of said loops, and circuit controllers each having normally open closable contacts serially connected in one and the other of said loops, respectively, at adjacent portions thereof, one of the 2. In a signaling system, a signal circuit comprising two parallel loops, sistanee connection between one end of one of said loops and the opposite end of the other thereof, signal manifesting means arranged for response to variations of current flow through said connection, a current source connected between the remaining ends of said loops, signal devices each having a differentially wound electromagnet, magnet windings of succeeding devices connected in alternate ones of said loops, and circuit controllers each having normally. open closable contacts serially connected in one and the other of said loops, respectively, at adjacent portions thereof, one of the contacts of each controller connected in a portion of one or the other of said loops which is situated between' the differential magnet windings of one or another of said signal devices.

3. In a signaling system, a signal circuit comprising two parallel loops, signal manifesting means connected between loops and the opposite end of the other thereof, a current source and signal manifesting means connected between the remaining ends of said loops, signal devices each having a differentially wound electromagnet, magnet windings of succeeding devices connected in alternate ones of said loops, and circuit controllers each having normally open closable contacts serially connected in one and the other of said loops, respectively, at adjacent portions thereof, one of the contacts of. each controller connected in a portion o`f..o ne or the other of said loops which is l magnet windings of one or another of said signal devices.

4. In a signaling system, a signal circuit comprising two parallel loops, signal inanitesting means connected between one end of one 'of said loops and the opposite end of the other thereof, a curi-ent source connccted between the remaining ends of said loops, signal devices each having a-ditler entially wound electromagnet, magnet windings of succeeding devices connected in4 alternate ones of said loops, and circuit controllers each having normally open closable contacts serially connected in one and the other of said loops, respectively, at adjacent portions thereof, one of the contacts of each controller connected in a. portion of one or the otherof said loops which is situated between the differential magnet windings of one or another of said signal devices.

5. In a signaling system, a signal circuit comprising two pa allel loops, a high resistance connection between one end ofoiie of said loops and the opposite end of the other thereof, a current source and signal manifesting means connected between the 'emaining ends of said loops, signal devices each having a differentially wound electromagnet, magnet windings of succeeding devices connected in alternate ones of said loops, circuit controllers each having normally open closable contacts'serially connected in one and the other of said loops, respectively, atadjacent portions thereof, one of the contacts of each controller connected in aportion of one or the other of said loops which is situated between the differential magnet -windings of one or another of said signal devices.

6. .In a signaling system, comprising two parallel loops, one end of oneof whichis connected to the opposite end lof the other thereof, a current source and signal manifesting means connected between the remaining ends of said loops, sig nal devices each having a differentially wound electromagnet, magnet windings of succeeding devices connected in alternate ones of said loops, and circuit controllers each having normally open closable cont-,acts serially connected in one and the other of said loops, respectively, at adjacent portions thereof, one of the contacts -of each controller connected in a portion of' one or the other of said loops which is situated between the differential magnet windings-'of one or another of said signal devices? 7. In a signaling system, a signal circuit comprising two parallel loops. a higliresistance connection between one end of said loops and the opposite end of the other thereof, a current source connected between.

a signal circuit situated between the differential .of said signalV devices.

lbetween the remaining end -signal devices each Y.from 'said ential magnet windings of the signal device mechanism andthe windings of the of said loops, signal det-he remaining ends a differentially wound vices cach having electromagnct, magnet vwindings of succecdy closable contacts serially one of the contacts of each controller con.-

nected in a portion of one orthe other o said loops which is situated between the differeiitial magnet windings of oiie'or another 8.In asignaling system, a signal .circuit comprising two parallel loops one end of one of which is connected to the opposite end of the other thereof, a current source connected slof said loops, having a differentially wound electroinagnet, magnet windings Aof succeeding devices connected in .alternate ones of said loops, and circuit controllers each having normally open closable contacts serially connected in one and the other of said loops, respectively, at adjacent portions thereof, one of the contacts of each controller connected in a portion of one or the other of said loops which is situated between the differential magnet windings of one or auother of said signal devices.

9. In ka signaling system, a signal circuit comprising two parallel loops one end of one of which is connected to the opposite end of the other thereof, a current source connected between the remaining ends of said loops, signal devices cach having a differentially wound electromagnet, magnet windings of succeeding devices connected in alternate ones of said loops, means associated with respective ones of-said devices for ca using effective energization of the differentially wound magnet thereof by establishing a connection from the portion of one of said loops which is situated between the differential magnet windings of such 'associated device and the other of said loops.

10. In a signaling s vstem, groups of circuit controllers eac-h controller having a normally open closable contact` a signal device associated with each group having a difierentially wound electromagnet` an alarm mechanism comprising a controlling electromagnct, a resistance for suitably limiting the normal current flow, a current source, and a system of conductors so arranged that a normal current path will be provided from said source, which path will include all of said` contacts and windings and said resists a`nce, and so that closure of the contactof any controller will establish a current path source including one of the di tierassociated with such controller signal de.- vicesland also the windings of said alarm alternate ones of the others of said signaldevicvs and excluding said resistance and the windings yof the remainder of said devices,

1l. In a signaling system, groups of circuit controllers each controller ha ving a normally open closable contact, a .signal device associated with each group having a differentiall)r wound electromagnet, alarm and supervisory manifesting mechanisms each comprising a controlling current source, and a system of conductors .so arranged that a normal current path will be provided from said source which path will include all of said contacts and windings,

and so that closure of the contacts of any controller will establish a current path from said source including one of the differential magnet windings of the signal device associated with sucln controller and also the windings of said alarm mechanism and the windings of the alternate ones of the other of said signal devices and excluding the windings of the remainder of said devices and of said snpernsory mechanism.

In Witness whereof, I hereunto snl,.':crihc my name this 29th day of August, 1922.

J OHN H. WOOTTON. 

